Exceptions.ipynb

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   "source": [
    "#Exceptions:\n",
    "x = 5\n",
    "z = 2\n",
    "# throw exception using raise keyword\n",
    "if z < 0:\n",
    "    raise ZeroDivisionError(\"Can't divide by zero\")"
   ]
  },
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   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "2\n"
     ]
    }
   ],
   "source": [
    "# test thing with assert\n",
    "x = 5\n",
    "z = 2\n",
    "assert (z > 0), \"can't divide by zero\"\n",
    "print(x // z)  # prints an int"
   ],
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     "name": "stdout",
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     "text": [
      "division by zero\n",
      "can't divide by zero\n"
     ]
    }
   ],
   "source": [
    "# try except block\n",
    "try:\n",
    "    z = 0\n",
    "    print(x / z)\n",
    "except ZeroDivisionError as z:\n",
    "    print(z)\n",
    "    print(\"can't divide by zero\")"
   ],
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   "cell_type": "code",
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    {
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     "text": [
      "division by zero\n",
      "can't divide by zero\n"
     ]
    }
   ],
   "source": [
    "# multiple except blocks\n",
    "try:\n",
    "    z = 0\n",
    "    print(x / z)\n",
    "except ZeroDivisionError as zde:\n",
    "    print(zde)\n",
    "    print(\"can't divide by zero\")\n",
    "except TypeError as te:\n",
    "    print(te)"
   ],
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   "cell_type": "code",
   "execution_count": 16,
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "1.6666666666666667\n"
     ]
    }
   ],
   "source": [
    "# you can have else close if no exception happened\n",
    "try:\n",
    "    z = 5\n",
    "    x = 3\n",
    "    res = z / x\n",
    "except Exception as e:\n",
    "    print(e)\n",
    "else:\n",
    "    print(res)"
   ],
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  {
   "cell_type": "code",
   "execution_count": 21,
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "5.0\n",
      "Division was done\n"
     ]
    }
   ],
   "source": [
    "# finally block: to clean up\n",
    "try:\n",
    "    z = 5\n",
    "    x = 1\n",
    "    res = z / x\n",
    "except Exception as e:\n",
    "    print(e)\n",
    "else:\n",
    "    print(res)\n",
    "finally:\n",
    "    print(\"Division was done\")"
   ],
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   "cell_type": "code",
   "execution_count": 23,
   "outputs": [
    {
     "ename": "MyException",
     "evalue": "2 is not acceptable here!",
     "output_type": "error",
     "traceback": [
      "\u001B[0;31m---------------------------------------------------------------------------\u001B[0m",
      "\u001B[0;31mMyException\u001B[0m                               Traceback (most recent call last)",
      "\u001B[0;32m/var/folders/9k/6fb9wvz9449bq955d8fnxskm0000gn/T/ipykernel_23118/3165381031.py\u001B[0m in \u001B[0;36m<module>\u001B[0;34m\u001B[0m\n\u001B[1;32m      4\u001B[0m \u001B[0mx\u001B[0m\u001B[0;34m=\u001B[0m \u001B[0;36m2\u001B[0m\u001B[0;34m\u001B[0m\u001B[0;34m\u001B[0m\u001B[0m\n\u001B[1;32m      5\u001B[0m \u001B[0;32mif\u001B[0m \u001B[0mx\u001B[0m\u001B[0;34m==\u001B[0m\u001B[0;36m2\u001B[0m\u001B[0;34m:\u001B[0m\u001B[0;34m\u001B[0m\u001B[0;34m\u001B[0m\u001B[0m\n\u001B[0;32m----> 6\u001B[0;31m     \u001B[0;32mraise\u001B[0m \u001B[0mMyException\u001B[0m\u001B[0;34m(\u001B[0m\u001B[0;34m\"2 is not acceptable here!\"\u001B[0m\u001B[0;34m)\u001B[0m\u001B[0;34m\u001B[0m\u001B[0;34m\u001B[0m\u001B[0m\n\u001B[0m\u001B[1;32m      7\u001B[0m \u001B[0;34m\u001B[0m\u001B[0m\n\u001B[1;32m      8\u001B[0m \u001B[0;34m\u001B[0m\u001B[0m\n",
      "\u001B[0;31mMyException\u001B[0m: 2 is not acceptable here!"
     ]
    }
   ],
   "source": [
    "# define custom exception\n",
    "class MyException(Exception):\n",
    "    pass  ## by using pass only you can send your own messages\n",
    "\n",
    "\n",
    "x = 2\n",
    "if x == 2:\n",
    "    raise MyException(\"2 is not acceptable here!\")"
   ],
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   "cell_type": "code",
   "execution_count": 26,
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "This number is not allowed here:  2\n"
     ]
    }
   ],
   "source": [
    "class MyValueException(Exception):\n",
    "    def __init__(self, message, value):\n",
    "        self.message = message\n",
    "        self.value = value\n",
    "\n",
    "try:\n",
    "    x = 2\n",
    "    if x == 2:\n",
    "        raise MyValueException(\"This number is not allowed here: \", x)\n",
    "except MyValueException as e:\n",
    "    print(e.message, e.value)"
   ],
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